Which of the following is not a primary color of light?

The primary colors of light are red, green, and blue. Yellow is a secondary color formed by combining red and green light.

Which vitamin is mainly synthesized by the human body when exposed to sunlight?

Vitamin D is synthesized in the skin when exposed to ultraviolet (UV) rays from sunlight.

Which organ in the human body is primarily responsible for filtering blood and producing urine?

The kidneys filter waste products, excess substances, and toxins from the blood to form urine.

What is the approximate pH of pure water at 25°C?

Pure water is neutral, with a pH of 7 at 25°C.

Which of the following is a good conductor of electricity?

Copper is a metal and an excellent conductor of electricity due to its free electrons.

The hardest naturally occurring substance is:

Diamond is the hardest known natural material due to its strong covalent bonds in a tetrahedral structure.

Which gas is most abundant in Earth's atmosphere?

Nitrogen makes up about 78% of Earth's atmosphere.

The process by which plants make food using sunlight is called:

Photosynthesis is the process by which green plants use sunlight to synthesize foods with the help of chlorophyll.

Which of the following is an example of a chemical change?

Rusting of iron involves a chemical reaction between iron, oxygen, and water, forming a new substance (rust).

Which of these is not a fossil fuel?

Uranium is a radioactive element used in nuclear energy, not a fossil fuel.

The unit of electric resistance is:

The ohm (Ω) is the SI unit of electrical resistance.

Which disease is caused by a deficiency of Vitamin C?

Scurvy is caused by a lack of vitamin C, leading to weakened connective tissues and gum disease.

Which part of the human brain controls balance and coordination?

The cerebellum is responsible for coordinating voluntary movements, balance, and posture.

Which of the following is a renewable source of energy?

Solar energy is renewable as it is derived from the sun, which is an inexhaustible source.

Which blood cells are primarily responsible for fighting infection?

White blood cells (leukocytes) are part of the immune system and help defend the body against infectious diseases.

The chemical formula of common table salt is:

Table salt is chemically known as sodium chloride (NaCl).

Which of these is a greenhouse gas?

Carbon dioxide is a greenhouse gas that traps heat in the atmosphere, contributing to global warming.

Which organelle is known as the 'powerhouse of the cell'?

Mitochondria produce ATP, the energy currency of the cell, through cellular respiration.

Sound cannot travel through:

Sound requires a medium (solid, liquid, or gas) to travel; it cannot travel through a vacuum.

Which metal is liquid at room temperature?

Mercury is the only metal that is liquid at standard conditions for temperature and pressure.

The normal body temperature of a healthy human is approximately:

The average normal body temperature is generally accepted as 37°C (98.6°F).

Which acid is present in the human stomach?

Hydrochloric acid is secreted in the stomach to aid digestion by breaking down food.

Which of the following is an example of a mammal that lays eggs?

The platypus is one of the few mammals that lay eggs instead of giving birth to live young.

Which part of a plant conducts water from roots to leaves?

Xylem is a vascular tissue in plants that transports water and minerals from the roots to the leaves.

The SI unit of force is:

The newton (N) is the SI unit of force, named after Sir Isaac Newton.

Which vitamin is also known as ascorbic acid?

Ascorbic acid is the chemical name for vitamin C.

The closest planet to the Sun is:

Mercury is the closest planet to the Sun in our solar system.

Which of the following is a vector quantity?

Velocity is a vector quantity because it has both magnitude and direction.

Which organ pumps blood throughout the human body?

The heart is a muscular organ that pumps blood through the circulatory system.

Which of the following is NOT a form of energy?

Mass is a measure of the amount of matter in an object, not a form of energy.